This invention relates to a mobile type radiography apparatus including an X-ray apparatus mounted on a moving truck to perform fluoroscopy and/or radiography by transporting the X-ray apparatus into a surgery room, and especially to a mobile type radiography apparatus suitable for performing examination or treatment by inserting a catheter into an object to be examined under observation of image.
The above mobile type radiography apparatus is a fluoroscopic and radiographic system capable of fluoroscopy or radiography for examination or surgery support by transporting the apparatus to a surgery room with a moving truck. In this system, an X-ray tube device (most of them are a mono-tank type integrally formed so as to include a high voltage generator and an X-ray collimator) is mounted on one end of a semi-circle type arm, i.e. so-called C-arm. An X-ray image reception device including, for example an image intensifier (hereinafter referred to as I.I.) and a television (TV) camera, is mounted on another end of the C-arm. The X-ray tube device and the X-ray image reception device are mounted on the C-arm so as to face each other for balancing the weight to acquire smooth and free motion of the X-ray tube device and the X-ray image reception device can be properly registered with an imaging part of the subject.
In the conventional mobile type radiography apparatus, a C-arm motion mechanism for registering the X-ray tube device and the X-ray image reception device supported by the C-arm with a part of subject subjected to fluoroscopy or radiography has a C-arm vertical motion mechanism for moving the C-arm and the X-ray tube device and the X-ray image receiving device, both supported by the C-arm (hereinafter referred to as an entire C-arm) in the vertical directions, a revolving mechanism for rotating the center of the entire C-arm around a rotation axis, of which direction is perpendicular to the longitudinal axial direction of the subject, a C-arm circular motion mechanism for rotating the C-arm along the arc, an C-arm swing mechanism for driving the entire C-arm to swing in the horizontal direction around the vertical motion axis, a C-arm front/back motion mechanism for forward and backward driving a central portion of the entire C-arm in the directions perpendicular to the longitudinal axial direction of the subject.
Although the mobile type radiography apparatus is most frequently used in the field of orthopedic surgery, it is also used in other fields because of their convenient movable feature advantageous for both of fluoroscopy and radiography.
For example, the mobile type radiography apparatus is used also in angiography""s field of head. Moreover, it is used in a treatment without incision to the body of the subject under an X-ray image observation (i.e. so-called Interventional Radiology, hereinafter referred to as IVR).
Such examination and treatment are to examine a thrombus or a contraction rate of vessels in a head, and to treat by dissolving the thrombus and enlarging contracted vessels. Therefore, it is necessary to insert a catheter for injecting a contrast medium and a solution for dissolving thrombus to the head vessel, and for inserting an instrument for enlarging the contracted vessels smoothly into the diseased part of the head while observing X-ray image.
In this case, it is necessary that the X-ray tube device and the X-ray image reception device supported by the C-arm are appropriately registered with the subject such that a fluoroscopic image of the catheter is displayed inside a monitor to catch the traveling of the catheter for guiding the catheter to the diseased part while identifying the location of the catheter with the mobile type radiography apparatus. This positioning method in a conventional apparatus will be explained in reference of FIGS. 4(a) and 4(b).
FIG. 4(a) is a perspective view showing relationship between the entire C-arm and the subject when the X-ray tube device and the X-ray image reception device are registered at a catheter inserting point O1 at a time of inserting a catheter from a vessel of heart.
First, a subject is laid with its back on a surgery bed. Then, the truck is positioned such that the C-arm of the X-ray device surrounds the subject on the surgery bed between the X-ray tube device 12 and X-ray image reception device 13 and a catheter inserting point O1 is located between X-ray tube device 12 and X-ray reception device 13. In use of a C-arm vertical motion mechanism, a center of X-ray irradiating field of the X-ray tube device is registered to coincide with the point O1. This registration is performed by properly using a revolving mechanism, a circular motion mechanism, a front/back motion mechanism in addition to the vertical motion mechanism. Point O0 in FIG. 4(a) designates a center of swinging axis of the C-arm swing mechanism for swinging the entire C-arm from left to right in the horizontal directions, and reference R designates a radius of the swinging locus.
Next, when a doctor inserts the tip of catheter from point O1 in FIG. 4(a) to point O2 in FIG. 4(a) or FIG. 4(b), being a diseased part (target of the treatment) of subject 21, the C-arm is moved by its swing motion under observation of fluoroscopic image of the catheter with the above C-arm swing mechanism. Then X-ray tube device 12 and X-ray image reception device 13, which are installed in the C-arm, are moved to point O3 in FIG. 4(b) along a circumference of swinging radius R. However, the location of point O3 differs from the location of target point O2 by xcex94L. Therefore, the correction of location is required as much.
Thus using the C-arm front/back motion mechanism, the location of the entire C-arm is moved from point O3 to point O2, and the location of xcex94L is corrected so that an irradiation center of X-ray tube device 12 corresponds with the target point O2.
Another positioning method is to register by moving the truck of C-arm in pursuit of traveling of the catheter tip from point O1 to point O2. However, because the weight of the entire apparatus mounted on this truck is 200 kg or more including the truck itself, it is hard to register by moving the truck (especially in a case where an operator is female). Either, in the case where the truck is moved to the small diseased part of the head vessels, sufficient accuracy of the registration is scarcely obtained. Therefore, the final and delicate registration should be conducted with the C-arm swing mechanism and the C-arm front/back motion mechanism.
As described, in the registration using the front/back motion or the combination of the swing mechanism and the front/back motion mechanism, a substantial time is necessary for the registration, whereby a time for fluoroscopy is elongated and an exposed amount of X-ray to a patient is increased.
Since the conventional mobile type radiography apparatus is designed so as to be used for orthopedic surgery as described above, an operation unit of the apparatus is placed on the top of the X-ray control unit, mounted on the truck. The arrangement of the operation unit is far away from an interconnecting line between the X-ray tube device and the X-ray image reception device. In a case of orthopedic surgery, even if the operation unit is located away from the line, there is no operational problem as long as the location of the X-ray tube device and the X-ray image reception device are not changed after these devices are once positioned for radiography. But when the tip of catheter is chased for imaging as in the above IVR, because the operation units has to be operated frequently, there is a problem that the unit is operated with difficulty when the control unit is positioned far away.
Furthermore, in the conventional mobile type radiography device, a cable for connecting the X-ray tube device with X-ray image reception device installed in the C-arm were wired on the outside of the C-arm to keep slack for enabling the C-arm rotation. Accordingly, there is a risk that the cable possibly is an obstacle to footstep of a doctor when he or she performs an IVR method in use of the mobile type radiography device, because the cable moves on a floor of surgery room when the apparatus is moved along with the moving of catheter tip.
The first object of the present invention is to provide a mobile type radiography apparatus suitable for performing an IVR method in reference to the above problems.
The second object of the present invention is to provide a mobile type radiography apparatus capable of performing fluoroscopy while chasing a catheter tip inserted in and moving through a subject to be examined when a doctor performs an IVR method.
The third object of the present invention is to provide a mobile type radiography apparatus having an operation unit suitable for performing an IVR method.
The forth object of the present invention is to provide a mobile type radiography apparatus, wherein a cable connecting an X-ray tube device with an X-ray image reception device is not obstacle to a doctor who performs an IVR method.
To solve the above object in the present invention, the mobile type radiography apparatus comprises a C-arm motion mechanism for linearly moving an entire C-arm in a longitudinal direction of a surgery bed under a state that a moving truck is positioned at a predetermined position with respect to the surgery bed; an operation unit arranged in a position where a doctor or the like can operate this when he or she stands in the vicinity of the C-arm; a cable for connecting an X-ray tube device with an X-ray image reception device, which cable accommodated in an inside of the C-arm; and a cable handling mechanism capable of respectively winding up and drawing out cables connected to the X-ray tube device and the X-ray image reception device in accordance with a circular motion of the C-arm.